Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
2,556
datasets available to search
ShareScore release 0.9.0
Dataset results
2,556 results for “assemblages”
Data from: Fish assemblage convergence along stream environmental gradients: an intercontinental analysis
Species that pass through similar environmental filters, regardless of geographic proximity or evolutionary history, are expected to share many traits, resulting in similar assemblage trait distributions. Convergence of assemblage trait distributions among different biotic regions would indicate that consistent ecological processes produce repeated patterns of adaptive evolution. This study analyzes trait-environment relationships across multiple stream fish assemblages representing evolutionarily divergent faunas. We hypothesized that trait-environment patterns converge across regional faunas in response to a common set of environmental filters acting on functional traits. One hundred and ninety-seven species and forty streams were sampled from five regions: Belize, Benin, Brazil, Cambodia, and United States of America. By examining trait-environment plots, multiple congruent trait-environment patterns were found across all regions, indicative of a consistent set of environmental filters acting on local community assembly. The consistency of these patterns strongly suggests that water velocity and habitat structural complexity function as universal environmental filters, producing similar assemblage trait distributions in streams across all regions. Bivariate relationships were not universal, and only one of the associations between a single functional trait and single environmental variable was statistically significant across all five regions. Strong phylogenetic signal was found in traits and habitat use, which implies that niche conservatism also influenced assemblage trait distributions. Overall, results support the idea that habitat templates structure trait distributions of stream fish assemblages and do so in a consistent manner.
Herbivore assemblage as an important factor modulating grazing effects on ecosystem carbon fluxes in a meadow steppe in northeast China
<p>A better understanding of how grazing by large herbivores, as the major land use worldwide, affects grassland carbon fluxes is critical for predicting future uptake of CO<span>2</span> in terrestrial ecosystem. Previous studies have focused on individual herbivore species; it remains poorly understood as to if and how herbivore assemblage (single- vs. mixed-species) would alter the impact of grazers on grassland carbon fluxes. Here we examined the effects of moderate grazing by different herbivore assemblages on net ecosystem CO<span>2</span> exchange (NEE), gross ecosystem productivity (GEP) and ecosystem respiration (ER) over the growing season in two types of grassland communities in a meadow steppe. We found that herbivore assemblages significantly affected NEE, and the effects varied in the two types of grassland communities. Compared to un-grazed grassland, mixed grazing of sheep and cattle increased NEE (i.e., increased CO<span>2</span> uptake) over the growing season regardless of community type, while sheep- or cattle-only grazing increased NEE in the low diversity community and decreased it in the high diversity community. Herbivore assemblages altered the NEE primarily via changing GEP. The different effects of herbivore assemblages on GEP may be attributed mainly to grazing-induced changes in soil water availability and canopy light availability. Our study indicates that mixed grazing of sheep and cattle might be an important grazing management practice to improve plant aboveground productivity and help mitigate CO<span>2</span> emissions during the growing season. It should be particularly used in diverse plant communities, where it might increase grassland carbon sequestration.</p>
Under the karst: detecting hidden subterranean assemblages using eDNA metabarcoding in the caves of Christmas Island, Australia
<p>Subterranean ecosystems are understudied and challenging to conventionally survey given the inaccessibility of underground voids and networks. In this study, we conducted a eukaryotic environmental (eDNA) metabarcoding survey across the karst landscape of Christmas Island, (Indian Ocean, Australia) to evaluate the utility of this non-invasive technique to detect subterranean aquatic 'stygofauna' assemblages. Three metabarcoding assays targeting the mitochondrial 16S rRNA and nuclear 18S genes were applied to 159 water and sediment samples collected from 23 caves and springs across the island. Taken together, our assays detected a wide diversity of chordates, cnidarians, porifera, arthropods, molluscs, annelids and bryozoans from 71 families across 60 orders. We report a high level of variation between cave and spring subterranean community compositions which are significantly influenced by varying levels of salinity. Additionally, we show that dissolved oxygen and longitudinal gradients significantly affect biotic assemblages within cave communities. Lastly, we combined eDNA-derived community composition and environmental (water quality) data to predict potential underground interconnectivity across Christmas Island. We identified three cave and spring groups that showed a high degree of biotic and abiotic similarity indicating likely local connectivity. This study demonstrates the applicability of eDNA metabarcoding to detect subterranean eukaryotic communities and explore underground interconnectivity.</p>
Data from: The influence of different aspects of grouse moorland management on non-target bird assemblages
1. Conflict between stakeholders with opposing interests can hamper biodiversity conservation. When conflicts become entrenched, evidence from applied ecology can reveal new ways forward for their management. In particular, where disagreement exists over the efficacy or ethics of management actions, research clarifying the uncertain impacts of management on wildlife can move debates forwards to conciliation. 2. Here, we explore a case-study of entrenched conflict where uncertainty exists over the impacts of multiple management actions: namely, moorlands managed for the shooting of red grouse (willow ptarmigan) Lagopus lagopus in the United Kingdom (UK). Debate over how UK moorlands should be managed is increasingly polarised. We evaluate, for the first time at a regional scale, the relative impacts of two major moorland management practices – predator control and heather burning – on non-target bird species of conservation concern. 3. Birds were surveyed on 18 estates across northern England and south-east Scotland. Sites ranged from intensively managed grouse moors to moorland sites with no management for grouse shooting. We hypothesised that both targeted predator control and burning regimes would enhance ground nesting wader numbers and, as a consequence of this, and of increased grouse numbers, non-target avian predators should also be more abundant on heavily managed sites. 4. There were positive associations between predator control and the abundance of the three most widespread species of ground-nesting wader: strong effects for European golden plover Pluvialis apricaria and Eurasian curlew Numenius arquata and, less strongly, for common snipe Gallinago gallinago. These effects saturated at low levels of predator control. Evidence for effects of burning was much weaker. We found no evidence of enhanced numbers of non-target predators on heavily managed sites.
Data from: A diverse neornithine assemblage from the Cretaceous Atlantic coastline and the rise of modern avifaunas
Extant birds (Neornithes) are one of the most widespread and diverse vertebrate lineages, but their early evolution is poorly understood. Although molecular analyses contend that most major extant bird lineages diverged during a period of explosive radiation following the Cretaceous-Paleogene (K-Pg) extinction, several enigmatic fossils from the latest Mesozoic suggest that some clades evolved before the end of the Cretaceous. We describe a historically collected bird assemblage from the Atlantic coastline and conclusively demonstrate its latest Cretaceous age. Phylogenetic analyses show these fossils are assignable to neornithines, and many may represent early members of Galloanseres (ducks, chickens, and kin). These fossils comprise the most diverse Mesozoic neornithine fauna known. Several of these neornithines had massive body masses reaching or exceeding those of the largest known Mesozoic birds and indicate that at least one family of wading birds, the Presbyornithidae, may have persisted through the K-Pg extinction event.The pronounced size variation observed in this assemblage indicates that early neornithines inhabiting coastal ecosystems were highly diverse and displayed tropic specialization comparable to modern coastal avifaunas.
Fire and grazing determined grasslands of central Madagascar represent ancient assemblages
<p>The ecology of Madagascar's grasslands is under-investigated and the dearth of ecological understanding of how disturbance by fire and grazing shapes these grasslands stems from a perception that disturbance shaped Malagasy grasslands only after human arrival. However, worldwide, fire and grazing shape tropical grasslands over ecological and evolutionary timescales, and it is curious Madagascar should be a global anomaly. We examined the functional and community ecology of Madagascar's grasslands across 71 communities in the Central Highlands. Combining multivariate abundance models of community composition and clustering of grass functional traits, we identified distinct grass assemblages each shaped by fire or grazing. The fire-maintained assemblage is primarily composed of tall caespitose species with narrow leaves and low bulk density. In contrast, the grazer-maintained assemblage is characterized by mat-forming, high bulk density grasses with wide leaves. Within each assemblage, levels of endemism, diversity and grass ages support these as ancient assemblages. Grazer-dependent grasses can only have co-evolved with a now-extinct megafauna. Ironically, the human introduction of cattle likely introduced a megafaunal substitute facilitating modern day persistence of a grazer-maintained grass assemblage in an otherwise defaunated landscape, where these landscapes now support the livelihoods of millions of people.</p>
Data from: Larval assemblages over the abyssal plain in the Pacific are highly diverse and spatially patchy
Abyssal plains are among the most biodiverse yet least explored marine ecosystems on our planet, and they are increasingly threatened by human impacts, including future deep seafloor mining. Recovery of abyssal populations from the impacts of polymetallic nodule mining will be partially determined by the availability and dispersal of pelagic larvae leading to benthic recolonization of disturbed areas of the seafloor. Here we use a tree-of-life (TOL) metabarcoding approach to investigate the species richness, diversity, and spatial variability of the larval assemblage at mesoscales across the abyssal seafloor in two mining-claim areas in the eastern Clarion Clipperton Fracture Zone (CCZ; abyssal Pacific). Our approach revealed a previously unknown taxonomic richness within the meroplankton assemblage, detecting larvae from 12 phyla, 23 Classes, 46 Orders, and 65 Families, including a number of taxa not previously reported at abyssal depths or within the Pacific Ocean. A novel suite of parasitic copepods and worms were sampled, from families that are known to associate with other benthic invertebrates or demersal fishes as hosts. Larval assemblages were patchily distributed at the mesoscale, with little similarity in OTUs detected among deployments even within the same 30 x 30 km study area. Our results provide baseline observations on larval diversity prior to polymetallic nodule mining in this region, and emphasize our overwhelming lack of knowledge regarding larvae of the benthic boundary layer in abyssal plain ecosystems.
Data from: Community assembly and climate mismatch in Late-Quaternary eastern North American pollen assemblages
Plant community response to climate change ranges from synchronous tracking to strong mismatch. Explaining this variation in climate change response is critical for accurate global change modeling. Here we quantify how closely assemblages track changes in climate (match/mismatch) and how broadly climate niches are spread within assemblages (narrow/broad ecological tolerance, or 'filtering') using data for the last 21 ka for 531 eastern North American fossil pollen assemblages. Although climate matching has been strong over the last 21 millennia, mismatch increased in 30% of assemblages during the rapid climate shifts between 14.5 to 10 ka BP. Assemblage matching rebounded towards the present day in 10-20% of assemblages. Climate-assemblage mismatch was greater in tree-dominated and high-latitude assemblages, consistent with persisting populations, slower dispersal rates, and glacial retreat. In contrast, climate matching was greater for assemblages comprising taxa with higher median seed mass. Over half of the assemblages were climatically filtered at any given time, with peak filtering occurring at 8.5 ka BP for nearly 80% of assemblages. Thus, vegetation assemblages have highly variable rates of climate mismatch and filtering over millennial scales. These climate responses can be partially predicted by species' traits and life histories. These findings help constrain predictions for plant community response to contemporary climate change.
Functional and genetic diversity changes through time in a cloud forest ant assemblage
<p>Climate change in the Neotropics is causing upslope range shifts. We used arrays of ant species collected in a cloud forest at 1,500 m in Área de Conservación Guanacaste (ACG), northwestern Costa Rica, collected in two time periods (1998-2000 and 2008-2011) to measure changes in species richness and diversity over a decade. Using metrics of community structure, we found that the species assemblage in the collections from the 1990s were significantly phylogenetically clustered and functionally less diverse as compared to collections from the early 2000's. At both time points, the assemblages were significantly phylogenetically clustered and while the difference in functional diversity between the time points was not significant, the ant assemblage has become lighter in color (on average) over time. When individual species are considered the overall pattern of replacement is consistent with the cloud forest ant assemblage being colonized by arrivals from lower-elevation forests. The invertebrate communities on cloud forested mountain tops are especially vulnerable to a changing climate as there are two factors working together; no higher terrain to which they can move and the invasion of more and more taxa from lower downslope. This vulnerability is already measurable.</p>
Data supporting the manuscript "Initial assemblage characteristics determine the functional dynamics of flower-strip plant communities"
<p>Original data recorded by the authors.</p>
Data from: Ocean warming affected faunal dynamics of benthic invertebrate assemblages across the Toarcian Oceanic Anoxic Event in the Iberian Basin (Spain)
<p>The Toarcian Oceanic Anoxic Event (TOAE; Early Jurassic, ca. 182 Ma ago) represents one of the major environmental disturbances of the Mesozoic and is associated with global warming, widespread anoxia, and a severe perturbation of the global carbon cycle. Warming-related dysoxia-anoxia has long been considered the main cause of elevated marine extinction rates, although extinctions have been recorded also in environments without evidence for deoxygenation. We addressed the role of warming and disturbance of the carbon cycle in an oxygenated habitat in the Iberian Basin, Spain, by correlating high resolution quantitative faunal occurrences of early Toarcian benthic marine invertebrates with geochemical proxy data (δ<sup>18</sup>O and δ<sup>13</sup>C). We find that temperature, as derived from the δ<sup>18</sup>O record of shells, is significantly correlated with taxonomic and functional diversity and ecological composition, whereas we find no evidence to link carbon cycle variations to the faunal patterns. The local faunal assemblages before and after the TOAE are taxonomically and ecologically distinct. Most ecological change occurred at the onset of the TOAE, synchronous with an increase in water temperatures, and involved declines in multiple diversity metrics, abundance, and biomass. The TOAE interval experienced a complete turnover of brachiopods and a predominance of opportunistic species, which underscores the generality of this pattern recorded elsewhere in the western Tethys Ocean. Ecological instability during the TOAE is indicated by distinct fluctuations in diversity and in the relative abundance of individual modes of life. Local recovery to ecologically stable and diverse post-TOAE faunal assemblages occurred rapidly at the end of the TOAE, synchronous with decreasing water temperatures. Because oxygen-depleted conditions prevailed in many other regions during the TOAE, this study demonstrates that multiple mechanisms can be operating simultaneously with different relative contributions in different parts of the ocean.</p>
Environmental DNA metabarcoding of cow dung reveals taxonomic and functional diversity of invertebrate assemblages
<p>Insects and other terrestrial invertebrates are declining in species richness and abundance. This includes the invertebrates associated with herbivore dung, which have been negatively affected by grazing abandonment and the progressive loss of large herbivores since the Late Pleistocene. Importantly, traditional monitoring of these invertebrates is time-consuming and requires considerable taxonomic expertise, which is becoming increasingly scarce. In this study, we investigated the potential of environmental DNA (eDNA) metabarcoding of cow dung samples for biomonitoring of dung-associated invertebrates. From eight cow pats we recovered eDNA from 12 orders, 29 families, and at least 54 species of invertebrates (mostly insects), representing several functional groups. Furthermore, species compositions differed between the three sampled habitats of dry grassland, meadow, and forest. These differences were in accordance with the species' ecology; for instance, several species known to be associated with humid conditions or lower temperatures were found only in the forest habitat. We discuss potential caveats of the method, as well as directions for future study and perspectives for implementation in research and monitoring.</p>
The fate of páramo plant assemblages in the sky islands of the northern Andes - Appendix S1. Vegetation and occurrence data used in this study
<p><strong>Aims:</strong> Assessing climate change impacts on biodiversity is a main scientific challenge, especially in the tropics, therefore, we predicted the future of plant species and communities on the unique páramo sky islands. We implemented the <i>Spatially Explicit Species Assemblage Modelling</i> framework, by i) calculating species' maximum dispersal distance, ii) modelling species distributions at present up to 2100, iii) assembling models into communities. Finally, we assessed the vulnerability of sky islands based on richness and composition changes.</p> <p><strong>Location: </strong>Ecuadorian super-páramo (>4200 m)</p> <p><strong>Methods:</strong> Using species trait data, the maximum dispersal distance of 435 species was calculated. Species distribution models (SDM) were fitted to obtain current and future distribution predictions based on dispersal and bioclimatic factors. The final assemblages for present and 2100 were achieved by stacking all probabilistic SDMs and applying the probability ranking rule. The vulnerability of each sky island was evaluated by quantifying richness and composition changes.</p> <p><strong>Results: </strong>Maximum dispersal distances ranged between 0.008-6027 m/year, and across all scenarios, 70% of models showed a net loss in species distribution while 9% of all species were predicted to undergo extinction by 2100. Local richness was estimated to decrease by 56.63% on average, and composition changes in each sky island suggested a mean loss of 64.74% of their original species pool against a 12.97% gain. Finally, 5% of the sky island floras reconverted from high-elevation to low-elevation species. These numbers were usually more important for high-elevation species and the mountains Pichincha, Ilinizas and Antisana.</p> <p><strong>Conclusions:</strong> Our study is methodologically pioneer and provides novel insight on the future of páramo biodiversity. Significant losses in species distribution and changes in community richness and composition suggest drastic impacts and call for further study considering additional factors, such as land-use. Finally, we recommend focusing monitoring and conservation strategies on the northern sky islands in priority.</p>
Data from: Drivers of assemblage-wide calling activity in tropical anurans and the role of temporal resolution
<p>1. Temporal scale in animal communities is often associated with seasonality, despite the large variation in species activity during a diel cycle. A gap thus remains in understanding the dynamics of short-term activity in animal communities.</p> <p>2. Here we assessed calling activity of tropical anurans and addressed how species composition varied during night activity in assemblages along gradients of local and landscape environmental heterogeneity.</p> <p>3. We investigated 39 anuran assemblages in the Pantanal wetlands (Brazil) with passive acoustic monitoring during the peak of one breeding season and first determined changes in species composition between night periods (early, mid, and late) using two temporal resolutions (1-hour and 3-hour intervals). Then, we addressed the role of habitat structure (local and landscape heterogeneity variables from field-based and remote sensing metrics) and ecological context (species richness and phylogenetic relatedness) in determining changes in species composition (i) between night periods and (ii) across days.</p> <p>4. Nocturnal calling activity of anuran assemblages varied more within the 1-hour resolution than the 3-hour resolution. Differences in species composition between early and late-night periods were related to local habitat structure and phylogenetic relatedness, while a low variation in compositional changes across days was associated with low-heterogeneous landscapes. None of these relationships were observed using the coarser temporal resolution (3-hour).</p> <p>5. Our findings on the variation of calling activity in tropical anuran assemblages suggest potential trades-off mediated by fine-temporal partitioning. Local and landscape heterogeneity may provide conditions for spatial partitioning, while the relatedness among co-signaling species provides cues on the ecological overlap of species with similar requirements. These relationships suggest a role of niche dimensional complementarity on the structuring of these anuran assemblages over fine temporal scales. We argue that fine-temporal differences between species in breeding activity can influence the outcome of species interaction and that addressing temporal scaling issues can improve our understanding of dynamics of animal communities.</p>
Livestock grazing is associated with seasonal reduction in pollinator biodiversity and functional dispersion but cheatgrass invasion is not: variation in bee assemblages in a multi-use shortgrass prairie
<p>Livestock grazing and non-native plant species affect rangeland habitats globally. These factors may have important effects on ecosystem services including pollination, yet, interactions between pollinators, grazing, and invasive plants are poorly understood. To address this, we tested the hypothesis that cattle grazing and site colonization by cheatgrass (Bromus tectorum) impact bee foraging and nesting habitats, and the biodiversity of wild bee communities, in a shortgrass prairie system. Bee nesting habitats (litter and wood cover) were marginally improved in non-grazed sites with low cheatgrass cover, though foraging habitat (floral cover and richness, bare soil) did not differ among cattle-grazed sites or non-grazed sites with low or high cheatgrass cover. However, floral cover was a good predictor of bee abundance and functional dispersion. Mean bee abundance, richness, diversity and functional diversity were significantly lower in cattle-grazed habitats than in non-grazed habitats. Differences in bee diversity among habitats were pronounced early in the growing season (May) but by late-season (August) these differences eroded as Melissodes spp. and Bombus spp. became more abundant at study sites. Fourth-corner analysis revealed that sites with high floral cover tended to support large, social, polylectic bees; sites with high grass cover tended to support oligolectic solitary bees. Both cattle-grazed sites and sites with high cheatgrass cover were associated with lower abundances of above-ground nesting bees but higher abundance of below-ground nesters than non-grazed sites with low cheatgrass cover. We conclude that high cheatgrass cover is not associated with reduced bee biodiversity or abundance, but cattle grazing was negatively associated with bee abundances and altered species composition. Although floral cover is an important predictor of bee assemblages, this was not impacted by cattle grazing and our study suggests that cattle likely impact bee communities through effects other than those mediated by forbs, including soil disturbance or nest destruction. Efforts aimed at pollinator conservation in prairie habitats should focus on managing cattle impacts early in the growing season to benefit sensitive bee species.</p>
Exploring the formation processes on open-air Palaeolithic sites: a late Middle Pleistocene Acheulean assemblage at Arbo site (Miño River basin, Spain)
<p>Dataset (.shp file) of lithic industry and natural clasts late Middle Pleistocene Acheulean assemblages at Arbo site.</p>
Taxon pulse dynamics, episodic dispersal, and host colonization across Beringia drive diversification of a holarctic tapeworm assemblage
Aim: We test the predictions of the Stockholm Paradigm, a synthesis of eco-evolutionary theory explaining the nature of faunal assembly, host range and parasite diversification. Faunal diversification and assembly, manifested in patterns of host colonization, co-adaptation and parasite speciation, is predicted to emerge as a consequence of alternating episodes of ecological disruption and stability. Specifically, for a diverse cestode genus (Arostrilepis), we evaluate the number and direction of Pleistocene dispersal events across Beringia, the number and relative timing of host colonization events, and the relationship between host and parasite biogeographic histories and associations through time. Location: Beringia and adjacent temperate to arctic biomes in North America and Eurasia. Taxon: Arostrilepis (Cyclophyllidea: Hymenolepididae) and its rodent hosts. Methods: Multi-locus phylogenetic reconstruction and biogeographic ancestral range estimation. Results: Arostrilepis lineages crossed Beringia eastward into North America a minimum of four times and westward into Asia twice in association with temporally disjunct geographic expansions of three major tribes of cricetid rodents (Arvicolini, Myodini, Lemmini). Inferences of ancestral host associations support at least nine instances of host-colonization involving shifts from one rodent tribe or family to another. Several previously unrecognized lineages of Arostrilepis are revealed. Main conclusions: Consistent with expectations of the Stockholm Paradigm, episodes of intercontinental dispersal were both frequent in the history of Arostrilepis and preceded a majority of inferred host-colonization events. Events of historical geographic expansion created numerous opportunities for development of novel host-parasite associations through ecological fitting, as parasites tracked historically conserved resources available across diverse host taxa. Beringia played a major role in shaping rodent/parasite assemblages by mediating dispersal between the northern continents during glacial episodes of the Pleistocene, rather than by serving as a zone of refugial isolation.
Data from: The present and future effects of land use on ecological assemblages in tropical grasslands and savannas in Africa
The world is currently experiencing a period of rapid, human-driven biodiversity loss. Over the past decade, numerous metrics for biodiversity have been used to create indicators to track change in biodiversity. However, our ability to predict future changes has been limited. In this study, we use two very different models to predict the status and possible futures for the composition and diversity of ecological assemblages in African tropical grasslands and savannas under land-use change. We show that ecological assemblages are affected more by land use in African grasslands and savannas than in other biomes. We estimate that average losses of assemblage composition and diversity are already between 9.7 and 42.0%, depending on the model and measure used. If current socio-economic trajectories continue ('business-as-usual'), the likely associated land-use changes are predicted to lead to a further 5.6–12.3% loss of assemblage composition and diversity. In contrast, a scenario that assumes more efficient use of agricultural areas (thus requiring a smaller total area) could be associated with a partial reversal ‒ of as much as 3.2% ‒ of past losses. While the agriculture that causes the majority of land-use change is an important source of economic growth, projections of the effects of land use on ecological assemblages can allow for more informed decisions.
Data from: Disassembly of an epibenthic assemblage in a sustained severely hypoxic event in a northeast Pacific basin
As global ocean deoxygenation proceeds and the frequency of extreme low-oxygen (hypoxic) events increases, seafloor ecosystems will inevitably be affected. Our study examines how benthic community responses scale with the severity and spatial extent of hypoxia. Saanich Inlet is a natural model system for testing the effects of hypoxic conditions that determine the benthic megafaunal community structure during annual deoxygenation and reoxygenation. In 2016, an anomalously severe and widespread hypoxic event occurred in the fjord after a decade of oxygen decline at a rate of 0.07 mL L−1 y−1 as measured by a cabled seafloor observatory. We use a living ecological time-series generated from remotely operated vehicle surveys to assess how the benthic megafaunal community disassembled in response to this extreme hypoxic event. Three benthic surveys at similar times in 2013 and 2016 reveal large increases in the area of seafloor bathed in anoxic and hypoxic waters in the latter year. Both bottom oxygen and species depth distributions shoaled from 2013 to 2016, accompanied by a 56% overall decline in megafauna. The abundant habitat-forming pennatulacean octocoral, Halipteris willemoesi, decreased in abundance by 92.3% from fall 2013 to fall 2016, and pandalid shrimp disappeared from the community. Hypoxia-tolerant species experienced milder losses, and two new species occurred in 2016 – one a predator on the coral. Co-occurrence analyses revealed loss of significant community segregation from 2013 to 2016, and a re-mix of pairwise species co-occurrences in the latter year. The loss of oxygenated habitat compressed species into narrower depth ranges and led to disassembly probably through niche space constriction, while decimation of some populations eliminated key community associations. Community fragmentation and disruption of interactions is a possible outcome for many marine benthic ecosystems as marine hypoxia intensifies.
Functional organization of woody plant assemblages along precipitation and human disturbance gradients in a seasonally dry tropical forest
<p>Chronic anthropogenic disturbances (CAD) and rainfall are important drivers of plant community assembly, but little is known about the role played by inter and intraspecific trait variation as communities respond to these pervasive forces. Here we examined the hypothesis that lower precipitation and higher CAD reduce both intra and interspecific trait variation in Caatinga dry forests. We sampled woody plants across 15 plots along precipitation and CAD gradients and measured resource-use traits. Effects of precipitation and CAD on RaoQ functional diversity were decomposed into species turnover and intraspecific variability. We used "T-statistics" to assess the trait sorting from the regional pool to local communities (i.e. external filtering), and within-community forces leading to low trait overlap (i.e. internal filtering) at individual- and species-level. Intraspecific variability explained at least one third of the total trait variation and 46% of variation in multitrait diversity across communities. Increasing disturbance reduced multitrait diversity, while precipitation affected some particular traits, such as wood density. Overall, precipitation determined species sorting across communities, while disturbance relaxed internal filters, leading to higher trait overlap within communities due to higher intraspecific variability.<b> </b>Our results suggest that<b> </b>the woody Caatinga flora contains a substantial amount of both inter and intraspecific trait variation. This variation is not randomly distributed within and across communities, but varies according to rainfall conditions and disturbance intensity. These findings reinforce the emerging idea that human-disturbances can reorganize plant communities at multiple scales and highlight trait variability as a key biological asset for the resilience of dry forests.</p>
ScienceDex guides
Understand access before you commit
These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.